I use the PI Calientoes toe covers on my road shoes (Northwaves) with an SPD-SL cleat...I had to get the XL size (my shoes are a size 42...yes I have clown feet) and they fit the shoes just fine. For rides where the temps start out in the 30's, I switch to PI full shoe covers (the Amfib material ones), also in a size XL which is the biggest size they make. They just fit (like barely) my shoes, but work great. I have to really pull the velcro closure together in the back, in order to get a good seal...but I haven't had any problems with them ripping and I love the rubber-like bottoms that they have. Way more durable and grippy on damp pavement.

I would say for those that are having problems with toe/shoe covers fitting over MTB shoes, perhaps try going up a size or two (if you can) and see if that helps. I find it odd, that although my PI shoe covers *just* fit over my shoes...when my DH has borrowed them on occasion, they actually seem to slide over his shoes much easier...and he wears a size 46 Specialized S-Works shoe with Speedplay cleats. Not sure why that is.

Linda